To gain a greater understanding of the control process which governs the transcription of protein-coding genes it is necessary to have a detailed molecular characterization of the steps involved. It is important to identify and isolate the components involved both at the level of initiation and termination of transcription. With a basic understanding of the underlying molecular process a more sophisticated conceptual framework for the overall problem of transcriptional control will be achieved. The research proposed in this application will address the issues of the basic molecular mechanisms of transcriptional initiation and termination. It is proposed that those initiation components which have already been identified be purified to homogeneity. One of the components has been purified extensively and shown to be a sequence specific DNA binding factor. This factor binds to a region of DNA known to be essential for the initiation of transcription in vitro, and in many cases in vivo. Thus, considerable progress has already been made in the characterization of one of the RNA polymerase II transcription factors. Another RNA polymerase II transcription factor which has been purified extensively and characterized is one which is specific for the Drosophila heat shock genes. This factor is also a sequence specific DNA binding factor which only binds to certain heat shock genes. Therefore, two transcription factors have already been characterized in some detail. One of these factors is perhaps a more general transcription factor, while the other is a very specific one for the heat shock genes. The proposed research will complete the purification of these two transcription factors and characterize their DNA binding and transcriptional properties as fully as possible. The research proposed will also lead to a more complete understanding of the other transcription factors involved both in the initiation of transcription as well as the processing of the Drosophila histone mRNA3' ends.